Abstract: Compared to ABO₃-type oxides, A₂B₂O₇-type oxides exhibit the superior properties due to their rich compositional elements, high tolerance and stability. These high-entropy ceramics have been proven to hold the great potential in various fields such as thermal barrier coatings, thermoelectrics, clean energy conversion, catalysts, functional modulation and energy storage batteries, ect. The structure and material systems, as well as recent experimental and theoretical research progress on A₂B₂O₇ high-entropy oxides, are reviewed. Additionally, the future focuses and challenges are discussed to provide a clear understanding of the development trends in this field for readers.